1. Prevalence of corneal astigmatism in cataract surgery candidates in Bangkok, Thailand Kaevalin Lekhanont, MD, Wadakarn Wuthisiri, MD, Porntip Chatchaipun, BSc, Anun Vongthongsri, MD Ramathibodi Hospital, Mahidol University The authors have no proprietary interest in any product or instrument used in this study

2. Purpose To evaluate the prevalence and characteristics of corneal astigmatism in senile cataract patients scheduled for cataract surgery

3. Methods Prospective study Institutional Review Board approved January 2007-October 2009 Cataract surgery candidates Inclusion criteria Presence of cataract Age ≥ 40 years old Exclusion criteria Corneal disease Irregular astigmatism Presence of pterygium Previous ocular surgery Uncooperative patient

4. Methods Presurgical screening examinations Keratometry (Topcon- KR8100) Manifest refraction Best-corrected visual acuity Slit-lamp examination Applanation tonometry Dilated fundus examination Statistical analyses STATA version 11 Mean, SD or median and range Describing continuous data Frequency and percentage Describing categorized data The level of significance at P < 0.05

5. Results 2010 eyes in 1005 patients CharacteristicValue Mean age (SD) (y)68.21 (9.19) Range of age (y)42-96 Gender (male/female)388/ 617 Median value of corneal astigmatism (D)0.88 (0-4.5) Mean keratometry (D) - Steepest meridian - Flattest meridian 44.91 ± 1.54 44.02 ± 1.56 Range of keratometry (D)38-49

6. Prevalence of corneal astigmatism Corneal Astigmatism (D) Prevalence (%)95%CI ≤0.520.9717.31-25.01 >0.5-143.4938.87-48.19 >1-228.9224.78-33.33 >2-35.303.42-7.78 >31.320.49-2.86 35.5% of the eyes had corneal astigmatism ≥ 1.25D

7. Corneal astigmatism in the age groups Corneal astigmatism increased with age (P <0.01)

8. Axis distribution [22.06-30.34] [8.88-15.02] [57.61-66.73]

9. Astigmatic axes in the age groups ATR astigmatism increased with age (P <0.001)

10. Discussion Attempted to determine the prevalence of different amounts of corneal astigmatism A few such reports are available in the literature Prevalence of corneal astigmatism increased with age, particularly ATR direction, similar to previous studies Provide a useful information for cataract surgeon Several options for correcting corneal astigmatism at the time of cataract surgery may be considered

11. StudiesFerrer- Blasco et al, 2009 Riley et al, 2001 Gonzalez et al, 2007 Present study, 2009 Eyes/ patients4540/2415502/488N/A2010/1005 Age60.59±9.8774.9±9.8N/A68.21±9.19 Sex68.2% F62% FN/A61.37% F Corneal astigmatism ≥ 1 D 34.8%N/A63%37.8% Mean corneal astigmatism 0.90±0.930.9±0.8 0.75 (median) N/A1.05±0.62 0.88 (median) Range of astigmatism 0.0-6.750.0-6.50N/A0.0-4.50 Axis of astigmatismN/A50% ATRN/A62% ATR Mean steepest K (D)44.08±1.6144.1±1.7N/A44.91 ± 1.54 Range of K (D)38-4838.6-50.5N/A38-49

12. Conclusions The prevalence of corneal astigmatism > 1 D was 35.5% in this study population Emphasize the importance of considering preexisting corneal astigmatism in senile cataract patients prior to surgery to achieve the optimal postoperative refractive outcomes Thank you for your attention